What do you mean by pinch off voltage, Electrical Engineering

Assignment Help:

Q. What do you mean by Pinch off voltage?

As the voltage Vds is increased from 0 to a few volts, the drain current will increase as  determined by Ohm's law and the plot of Id versus Vds will appear as shown below. The relative straightness  of the plot reveals that for a region of lower values of Vds, the resistance is essentially a constant. As Vds increases and reaches a level called Vp the depletion region widens causing reduction in the channel width, this reduction in channel width causes the resistance to increase and forces a curve in the graph. This level of voltage Vp is called pinch off voltage. Actually pinch off is the condition at which both the p parts touch thus blocking the current. But this doesn't really happen. The current Id maintains a saturation level referred to as Idss because of the existence of a very small channel with high density current.  As Vds is increased after attaining Vp, the region of close encounter between the 2 deletion regions will increase, but the kevel of Id remains essentially the same. In essence therefore once Vds > Vp, the JFET has the characteristics of a current source.


Related Discussions:- What do you mean by pinch off voltage

Congestion, It is uneconomic to provide adequate equipment to carry all the...

It is uneconomic to provide adequate equipment to carry all the traffic which could possibly be offered to a telecommunication system. In a telephone exchange it's theoretically po

What do you mean by negative clamper, Q. What do you mean by Negative Clamp...

Q. What do you mean by Negative Clamper? During the positive half cycle the diode conducts and acts like a short circuit. The capacitor charges to peak value of input voltage V

1-phase half bridge inverters, 1- Φ Half Bridge Inverters 1-Φ bridge  ...

1- Φ Half Bridge Inverters 1-Φ bridge  inverter may be  of two  type 1-? half  bridge  and 1-? full  bridge  inverter. 1-? half bridge  inverter with resistive load to explain

Value of current if resistance connected to the battery, One battery having...

One battery having of eight cells in parallel. Emf and internal resistance of every cells is 1.5V and 0.4Ω. Find the value of current if an external resistance of 5Ω is connected t

Ac resistance and dc resistance, Background Information Electrical mach...

Background Information Electrical machines usually consist of copper windings on steel cores, and their AC resistance is greater than their DC resistance. The power loss has

A transistor has how many p-n junction, A transistor has (A) One p-n j...

A transistor has (A) One p-n junction.  (B) Two p-n junction. (C) Four p-n junction. (D) Five p-n junction. Ans: A transistor has two p-n junctions.

Describe the lastprivate clause, Q. Describe the Lastprivate Clause? Th...

Q. Describe the Lastprivate Clause? The lastprivate clause declares one or more list items to be private to a thread in additin causes corresponding original list item to be up

Determine the speed of prime mover of the generator, A synchronous generato...

A synchronous generator has a rotor with six poles and operates at 60 Hz. (a) Determine the speed of prime mover of the generator. (b) Repeat part (a) if the generator has 12

Low and high pass filters - calculate the cutoff frequencies, At the comple...

At the completion of this unit, you will be able to determine the cutoff frequencies and attenuations of RC and RL low- and high-pass filters by using test circuits. UNIT FUNDA

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd